Technical details: the GUI is done with the Gtk2 library, the Glade3 interface builder, and the Python programming language, while the internal engine remains in C++ and SDL. Pygame is also used to initialize SDL, this way we may manipulate the SDL window from Python if need be.

Python and C++ are tied together through GObject-based bindings (as PyGtk does), and Gtk and SDL are coupled using a brand new PyGtkSDL widget by yours truly (using the SDL_WINDOWID technique + close Gtk integration).

I may switch from C++ to C+GObject for the engine internals in the near future.